How to set HTTP proxy?

I’m trying to use OSMC in China and lots of services are blocked. To get around this I have a proxy server available over a PPTP link at 192.168.76.1. Is there any way to configure OSMC to use that for all HTTP requests? Normally I would find that in the “network” settings somewhere but I can’t see anything relevant.

For within Kodi please check this out http://kodi.wiki/view/Settings/System
For the OS level there is currently no single solution for it but you could try to add

export http_proxy=http://username:password@proxyserver.net:port/
export ftp_proxy=http://username:password@proxyserver.net:port/

to bashrc

Ah! It requires “advanced” mode. Great, thanks!